Asynchronous ubiquitous protocol

ABSTRACT

Disclosed is a method for requesting data from a set of remote units in a network, the method comprising: defining an Asynchronous Ubiquitous Protocol, the Asynchronous Ubiquitous Protocol comprising a schedule of a plurality of time slots, each time slot defined by a distinct start time and end time pair; broadcasting transmitting instructions to the set of remote units, the transmitting instructions comprising the Asynchronous Ubiquitous Protocol and selection instructions for selecting a time slot from the Asynchronous Ubiquitous Protocol to use for data transmission; and, receiving data transmitted from a remote unit in the set of remote units in accordance with the transmitting instructions.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.15/463,044 filed Mar. 20, 2017 which is a continuation of U.S.application Ser. No. 14/212,089 filed Mar. 14, 2014 which claimspriority from U.S. provisional patent application No. 61784146, filed onMar. 14, 2013. The contents of these prior applications are incorporatedherein by reference.

FIELD

The present disclosure relates to transmission of data and in particularto the transmission of data from a one or more out of a set of remoteunits to a base unit.

BACKGROUND

Often communication networks include a number of remote units thatcommunicate with a base unit. For example, this type of network can beimplemented for an event system network.

Networks such as communication networks often have a base unit stationwhere the individual event reporting units or remote units aremonitored. For example, remote units may be located throughout a city orgeographical region. The base unit may be responsible for monitoringeach remote unit. When an emergency is detected at the remote unit, theremote unit may have to notify the base unit that an emergency isdetected.

There may be situations in which a base unit is responsible for manythousands of remote units. If many remote units are transmitting datasimultaneously to a base unit, there may be a risk of transmissionsignals clashing.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made, by way of example, to the accompanyingdrawings which show example embodiments of the present application andin which:

FIG. 1 is a block diagram illustrating a communication network;

FIG. 2 is a block diagram illustrating components of a remote unit;

FIG. 3 is a block diagram illustrating components of a base unit;

FIG. 4 is a schematic diagram of an exemplary Asynchronous UbiquitousProtocol;

FIG. 5 is a flow chart depicting a method for requesting data from a setof remote units in a network;

FIG. 6 is a flow chart depicting a method of transmitting data from aremote unit to a base unit;

FIG. 7 is a schematic diagram of a memory of a remote unit showing alist of hop destinations and a list of eligible hop destinations;

FIG. 8 is a flow chart depicting a method of managing one or moretransmission routes for a remote unit in a communication network; and

FIG. 9 is a flow chart depicting a method of managing the transmissionroutes in a communication network.

Like reference numerals are used in the drawings to denote like elementsand features.

DETAILED DESCRIPTION

According to one aspect disclosed is a method for requesting data from aset of remote units in a network, the method comprising: defining anAsynchronous Ubiquitous Protocol, the Asynchronous Ubiquitous Protocolcomprising a schedule of a plurality of time slots, each time slotdefined by a distinct start time and end time pair; broadcastingtransmitting instructions to the set of remote units, the transmittinginstructions comprising the Asynchronous Ubiquitous Protocol andselection instructions for selecting a time slot from the AsynchronousUbiquitous Protocol to use for data transmission; and, receiving datatransmitted from a remote unit in the set of remote units in accordancewith the transmitting instructions.

According to another aspect, disclosed is a method of transmitting datafrom a remote unit to a base, the method comprising: receivingtransmitting instructions from the base, the transmitting instructionscomprising an Asynchronous Ubiquitous Protocol and instructions forselecting a time slot from the Asynchronous Ubiquitous Protocol, theAsynchronous Ubiquitous Protocol comprising a schedule of a set of timeslots each defined by a start time and end time pair; selecting a timeslot from the Asynchronous Ubiquitous Protocol within which to transmitremote unit data, the selection based on the instructions for selectingthe time slot; and transmitting the data to the base in accordance withthe selected time slot.

According to another aspect, disclosed is a communication network forreducing signal collision when transmitting data from one or more remoteunits out of a set of remote units, the network comprising: a set of oneor more remote units, each remote unit arranged to transmit data; a basefor communicating with the set of one or more remote units and formanaging the communication network, the base associated with a databaseand with a processor, the processor configured to: define anAsynchronous Ubiquitous Protocol, the Asynchronous Ubiquitous Protocolcomprising a schedule of plurality of time slots, each time slot definedby a distinct start time and end time pair; broadcast transmittinginstructions the set of remote units, the transmitting instructionscomprising the Asynchronous Ubiquitous Protocol and selectioninstructions for selecting a time slot from the Asynchronous UbiquitousProtocol to use for data transmission; and, receive data transmittedfrom one of the remote units in the set of one or more remote units inaccordance with the transmitting instructions.

According to another aspect, disclosed is a remote unit for transmittingdata across a network to a base, the remote unit comprising: a memoryfor storing instructions; a processor for executing instructions storedon the memory in order to: receive transmitting instructions from thebase, the transmitting instructions comprising an AsynchronousUbiquitous Protocol and instructions for selecting a time slot from theAsynchronous Ubiquitous Protocol, the Asynchronous Ubiquitous Protocolcomprising schedule of a set of time slots each defined by a start timeand end time pair; select a time slot from the Asynchronous UbiquitousProtocol within which to transmit remote unit data, the selection basedon the instructions for selecting the time slot; and transmit the datato the base in accordance with the selected time slot.

Exemplary Communication network

For convenience, like numerals in the description refer to likestructures in the drawings. Referring to FIG. 1, an exemplarycommunication network is illustrated generally by numeral 100. Thecommunication network 100 includes one or more remote units 102 and oneor more base unit stations 104 (or base units). The communicationnetwork 100 may also include a base collector 106.

The remote units 102 can be configured to transmit data to the base unit104 or to one or more neighboring remote units 102 or to a nearby basecollector 106. The remote units 102 can also be configured to transmit apolling message such as an indication that the remote unit 102 is activeor an indication that the remote unit 102 is operational (in that it canfunction to transmit a message to the base unit 104).

The base unit 104 and remote units 102 can transmit data over a RadioFrequency (RF) network. Similarly, the base collectors 106 can transmitdata over a RF network. For example, the base unit 104 and remote units102 may be configured to transmit data using a single RF channel. Thebase unit 104 can have a range of transmission that allows it totransmit data to all of the remote units 102. For instance, the baseunit 104 can broadcast a message over an RF channel to each remote unit102 within its transmission range. The transmission range of the baseunit 104 is depicted in FIG. 1 using the directed arrows. The directionof the arrows indicates the direction of transmission. The base unit 104can transmit data to each of remote units 102 labelled A, B, C, D and Eand to the base collector 106.

In one or more embodiments, the base unit 104 can broadcast instructionsand messages and the base collector(s) 106 can rebroadcast the receivedinstructions. Such a configuration may be useful in implementations inwhich the base unit 104 transmission does not reach all of the desiredareas of the communication network 100. This may occur if there areremote units 102 that are not within the transmission range of the baseunit 104.

The base unit 104 is responsible for managing the communication witheach remote unit 102, handling event messages transmitted from theremote units 102, and managing and updating a database of remote units102 and event codes.

Each remote unit 102 has a limited range of transmission. For example, aremote unit 102 may only be capable of transmitting data to aneighboring remote unit 102. Referring to FIG. 1, remote unite 102 A cantransmit data to remote unit 102 B, the base unit 104, the basecollector 106 and remote unit 102 E. Remote unit 102 B can transmit datato remote unit 102 A, remote unit 102 C, and remote unit 102 D. Remoteunit 102 C can transmit data to remote unit 102 A. Remote unit 102 D cantransmit data to remote unit 102 B and remote unit 102 E. Remote unit102 E can transmit data to remote unit 102 A, remote unit 102 B and thebase collector 106.

The remote units 102 can receive data from other remote units 102(assuming the other remote units 102 have adequate transmission range)and from the base unit 104.

Depending on the data (e.g. on the contents of the data) the remoteunits 102 may retransmit received data. For example, data that isreceived from another remote unit 102 may be retransmitted for receiptby another remote unit 102 or a base collector 106 or the base unit 104(if within transmission range).

Thus, for remote unit 102 C to transmit data to the base unit 104, thedata can follow one of the following paths:

1. Remote unit 102 C to remote unit 102 B to remote unit 102 A to thebase unit 104;

2. Remote unit 102 C to remote unit 102 B to remote unit 102 A to thebase collector 106 to the base unit 104;

3. Remote unit 102 C to remote unit 102 B to remote unit 102 A to remoteunit 102 E to the base collector 106 to the base unit 104;

4. Remote unit 102 C to remote unit 102 B to remote unit 102 D to remoteunit 102 E to the base collector 106 to the base unit 104;

5. Remote unit 102 C to remote unit 102 B to remote unit 102 D to remoteunit 102 E to remote unit 102 A to the base collector 106 to the baseunit 104; and

6. Remote unit 102 C to remote unit 102 B to remote unit 102 D to remoteunit 102 E to remote unit 102 A to the base unit 104.

Each transmission from a remote unit 102 to another remote unit 102 canbe identified as a hop. In one or more embodiments, if a remote unit 102receives a data transmission from another remote unit 102 the receivingremote unit 102 can include further identifying data (“hop data”) to thetransmission to indicate that it retransmitted the data.

The remote units 102 can monitor the data that is transmitted fromneighboring remote units 102 (i.e. remote units 102 within transmissionrange). For example, with reference to FIG. 1, remote unit 102 A canmonitor transmissions emanating from remote unit 102 B, and remote unit102 E. Remote unit 102 A can also monitor transmissions from the basecollector 106. Remote unit 102 B can monitor transmissions emanatingfrom remote unit 102 A, remote unit 102 C, and remote unit 102 D. Remoteunit 102 C can monitor transmissions emanating from remote unit 102 A.Remote unit 102 D can monitor transmissions emanating from remote unit102 B and remote unit 102 E. Remote unit 102 E can monitor transmissionsemanating from remote unit 102 A and remote unit 102 B.

A remote unit 102 that transmits data to a neighboring remote unit 102(i.e. a hop) can monitor the transmissions emanating from thatneighboring remote unit 102 (because it is within transmission range).For example, remote unit 102 D may transmit data to remote unit 102 E tofor retransmission. Remote unit 102 D may then determine that the datahas not been retransmitted after a pre-determined period of time andremote unit 102 D may then retransmit the data to remote unit 102 B(another neighbor on the hop list) for retransmission. Remote unit 102 Dmay then, from monitoring remote unit 102 B, determine that the data wasretransmitted (e.g. to remote unit 102 A). Similarly, remote unit 102 Bwill then monitor the retransmissions from remote unit 102 A to ensurethat the data was transmitted all the way to the base unit 104. Theremote unit 102 D may then change the order of an ordered (orprioritized) hop list that it maintains.

Each remote unit 102 can include (e.g. stored in an associated memory) alist of remote units 102 that are within its transmission range (i.e.that it can transmit data to). This list may be identified as a “hoplist”. Similarly, the remote unit 102 can order the hop list to createan ordered list of remote units 102. The list can be ordered based onone or more criteria such as location, past efficiency, hop distance,rank, communications facilities and the number of different routes atthe units in the hop list, etc. This ordered hop list can be stored in adatabase that is associated with the remote unit 102. The ordering ofneighboring remote units 102 in the ordered list can be amended orchanged by the remote unit 102 that is storing the ordered list. Thiscan happen, for example, in response to network conditions or a changein a status of a neighboring remote units 102 (e.g. if it is determinedthat the neighboring remote unit is not functioning properly. This canalso happen, for example, if the remote unit 102 discovers one or morenew (i.e. previously unknown or untested) remote units 102 that have abetter set of criteria than existing units in the hop list.

In one or more embodiments, the remote units 102 are event reportingunits. The remote units 102 may be associated with event systems. Theevent systems can be installed on buildings, for example, in order todetect unauthorized access to the building. For example, the eventsystem can have sensors (such as cameras or motion sensors) that detectwhether a person is attempting to access a building. The remote unit 102may be alerted by the event system or the sensors and may automaticallytransmit a message to the base unit 104 (e.g. using hops) notifying itof the potential unauthorized access to the building.

The remote units 102 may be constantly listening on a particular RFchannel for messages or data transmitted from the base unit 104 and fromother remote units 102 that are within frequency range. The remote units102 may gather network configuration information through suchinformation.

In one or more embodiments there may be many more remote units 102 ormany more base stations 106 than are depicted in FIG. 1. For example,the communication network 100 may cover the geographic region of a largecity and may include over 100,000 remote units 102.

One or more base collectors 106 can be distributed throughout thecommunication network 100. The base collectors 106 can be used tocollect data from neighboring remote units 102 (e.g. remote units 102for which the particular base collector 106 is in transmission range).The base collector 106 may have enough transmission range to transmitdata to the base unit 104. Alternatively, the base collectors 106 may beconfigured to transmit data to the base unit 104 on an alternativechannel or using a different network or different protocol.

In one or more embodiments, the communication network 100 can be dividedinto geographical regions. The geographical regions may be distinct inthat each remote unit 102 is in at most one geographical region. Eachbase collector 106 may be associated with a distinct geographicalregion. For example, each geographical region may be associated with adistinct base collector 106.

In one or more embodiments, the base collectors 106 can be configured totransmit data to and received data from the base unit 104 over aseparate communication channel or using a separate communicationprotocol. For example, the base stations 106 can communicate with thebase unit 104 using a different RF channel than is used by the remoteunits 102. By way of further example, the base stations 106 cancommunicate with the base unit 104 using Internet Protocol.

The data transmitted from a remote unit 102 destined for the base unit104 can include the identity of the remote unit 102 (e.g. serial number)and an identification of the type of event being reported. Theidentification of the type of event being reported can include an eventcode, which may be decipherable at the base unit 104. The geographiclocation of the remote unit 102 or its associated event system can bestored in a memory (e.g. a database) associated with base unit 104. Forexample, there may be an event code representing a broken window in ahouse where the event system is installed and there may be a differentevent code for an unauthorized access through a door to a building wherethe event system is installed.

It is understood that the data can be encrypted.

At any given time, the number of remote units 102 that have an event toreport is likely much fewer than the total number of remote units 102within the communication network 100. However, there may be times whenthe number of remote units 102 that have an event to report is muchcloser to the total number of remote units 102 within the communicationnetwork 100, such as a weather-related event or power outage or otherevent that effects most event systems.

FIG. 2 shows the components of an exemplary remote unit 102 in detail.The remote unit 102 may be associated with an event system at aparticular address. For example, the remote unit 102 can receive sensorinformation from one or more sensors in the event system or the remoteunit 102 can receive sensor data from the event system.

The remote unit 102 can be a two-way communication device having thecapability of receiving and transmitting data to other communicationsystems (such as other remote units 102, base collectors 106 and baseunit 104). For example, the remote unit 102 may be configured totransmit data using various protocols, media and transmission systemsincluding RF, Z-Wave, ZigBee, Telephone, Cellular, WiFi, Infrared,Internet (IP), GPS module and Laser. In one or more embodiments, thetransmission range of the remote unit 102 may be limited to a selectionof nearby remote units 102 (or nearby base collectors 106 or base unit104)>

The remote unit 102 includes a communication subsystem 211, whichincludes a receiver 212, a transmitter 214, and associated components,such as one or more embedded or internal antenna elements 216 and 218,local oscillators (LOs) 213, and a processing module such as a digitalsignal processor (DSP) 220. As will be apparent to those skilled infield of communications, the particular design of the communicationsubsystem 211 depends on the communication network in which the remoteunit 102 is intended to operate.

The remote unit 102 includes a processor 238, which controls generaloperation of the remote unit 102. The processor 238 can interact withadditional device subsystems such as a random access memory (RAM) 226, aread only memory (ROM) 248, a data port 230 a short-range communicationssubsystem 240 such as Bluetooth^(TM) for example, and any other devicesubsystems or peripheral devices generally designated at 242.

Operating system software used by the processor 238 may be stored in apersistent store such as a ROM 248 or similar storage element (notshown). The operating system, specific device applications, or partsthereof, may be temporarily loaded into a volatile store such as RAM226.

The processor 238, in addition to its operating system functions,enables execution of software applications on the remote unit 102. Apredetermined set of applications, which control basic deviceoperations, is installed on the remote unit 102 during its manufacture.These basic operations typically include data communicationapplications, for example.

Additionally, applications may also be loaded onto the remote unit 102through the communication network 100, an auxiliary I/O subsystem 228,data port 230, short-range communications module 240, or any othersuitable subsystem 242, and installed by a user in RAM 226 or ROM 248,for execution by the processor 238. Such flexibility in applicationinstallation increases the functionality of the remote unit 102 and mayprovide enhanced on-device features, communication-related features, orboth.

The processor 238 can also be associated with an analog to digitalconvertor (ADC) 262, a zone input controller 264 and a DC power supply266. The ADC is connected to the processor 238 and is responsible forconverting analog signals to digital signals and vice versa. The zoneinput controller 264 is connected to the processor 238 and isresponsible for mapping and controlling the communication between theremote unit 102 and other devices at the premises where the associatedevent system is installed.

The short range communication module 240 provides for communicationbetween the remote unit 102 and different systems or devices, which neednot necessarily be similar devices. For example, the short rangecommunication module 240 may include an infrared device and associatedcircuits and components, or a wireless bus protocol compliantcommunication mechanism such as a Bluetooth® communication module toprovide for communication with similarly-enabled systems and devices.

In some example embodiments, the auxiliary input/output (I/O) subsystems228 may include an external communication link or interface, forexample, an Ethernet connection.

The remote unit 102 may include other wireless communication interfacesfor communicating with other types of wireless networks; for example, awireless network such as an orthogonal frequency division multiplexed(OFDM) network.

The remote unit 102 also includes a battery 256 as a stand-by powersource. The battery 256 can be used in the event of a power outage, forexample. In one or more embodiments, the battery 256 can be rechargeablethat may be charged, for example, through charging circuitry coupled toa battery interface 254 such as the data port 230. The battery 256 canprovide electrical power to at least some of the electrical circuitry inthe electronic device 102, and the battery interface 254 provides amechanical and electrical connection for the battery 256. The batteryinterface 254 is coupled to a regulator (not shown) which provides powerV+ to the circuitry of the remote unit 102.

The processor 238 may also be connected to an event system 290, such asan event detection system in a building or a home monitoring system. Theevent system 290 can be connected to at least one sensor 292. The sensor292 can be of various types, such as a motion sensor (or camera),specific sensors that monitor the entrance of individuals intobuildings, access control units, process control systems, which may beautomated.

FIG. 3 shows the components of an exemplary base unit 104 in detail.Generally, the base unit 104 manages and monitors various components andconditions in the communication network 100.

The base unit 104 can be a two-way communication device having thecapability of receiving and transmitting data to other communicationsystems (such as remote units 102 and base collectors 106). For example,the base unit 104 may be configured to transmit data using variousprotocols, media and transmission systems including RF, Z-Wave, ZigBee,Telephone, Cellular, WiFi, Infrared, Internet (IP), GPS module andLaser. The base unit 104 can be configured to broadcast messages to allof the components in the communication network 100. In other words, thebase unit 104 can have a transmission range that reaches or all of thecomponents in the communication network 100. It is recognized that insome implementations the topology of the communication network 100 maybe such that the transmission range of the base unit 104 does not extendto reach each remote unit 102. In such implementations the transmissionrange of the base unit 104 need only reach the base collectors 106 whichcan in turn retransmit the data received from the base unit 104.

The base unit 104 can be a communication subsystem 211, which includes areceiver 212, a transmitter 214, and associated components, such as oneor more embedded or internal antenna elements 216 and 218, localoscillators (LOs) 213, and a processing module such as a digital signalprocessor (DSP) 220. As will be apparent to those skilled in field ofcommunications, the particular design of the communication subsystem 211depends on the communication network (e.g. the communication network100) in which the base unit 104 is intended to operate.

The base unit 104 includes a processor 238, which controls generaloperation of the base unit 104. The processor 238 can interact withadditional device subsystems such as a random access memory (RAM) 226, aread only memory (ROM) 248, a data port 230 a short-range communicationssubsystem 240 such as Bluetooth™ for example, a user interface 390, andany other device subsystems or peripheral devices generally designatedat 242.

Operating system software used by the processor 238 may be stored in apersistent store such as a ROM 248 or similar storage element (notshown). The operating system, specific device applications, or partsthereof, may be temporarily loaded into a volatile store such as RAM226.

The processor 238, in addition to its operating system functions,enables execution of software applications on the base unit 104. Apredetermined set of applications, which control basic deviceoperations, is installed on the base unit 104 during its manufacture.These basic operations typically include data communicationapplications, for example. Additionally, applications may also be loadedonto the base unit 104 through the communication network 100, anauxiliary I/O subsystem 228, data port 230, short-range communicationsmodule 240, or any other suitable subsystem 242, and installed by a userin RAM 226 or ROM 248, for execution by the processor 238. Suchflexibility in application installation increases the functionality ofthe base unit 104 and may provide enhanced on-device features,communication-related features, or both.

The processor 238 can also be associated with an analog to digitalconvertor (ADC) 262, a zone input controller 264 and a DC power supply266. The ADC is connected to the processor 238 and is responsible forconverting analog signals to digital signals and vice versa.

The zone input controller 264 is connected to the processor 238 and isresponsible for mapping and controlling the communication between thebase unit 104 and other devices (such as the remote units 102 or thebase collectors 106 or event and monitoring devices in the monitoredpremises where the event system is located).

The short range communication module 240 provides for communicationbetween the base unit 104 and different systems or devices, which neednot necessarily be similar devices. For example, the short rangecommunication module 240 may include an infrared device and associatedcircuits and components, or a wireless bus protocol compliantcommunication mechanism such as a Bluetooth® communication module toprovide for communication with similarly-enabled systems and devices.

In some example embodiments, the auxiliary input/output (I/O) subsystems228 may include an external communication link or interface, forexample, an Ethernet connection. The base unit 104 may include otherwireless communication interfaces for communicating with other types ofwireless networks; for example, a wireless network such as an orthogonalfrequency division multiplexed (OFDM) network.

The base unit 104 also includes a battery 256 as a stand-by powersource. The battery 256 can be used in the event of a power outage, forexample. In one or more embodiments, the battery 256 can be rechargeablethat may be charged, for example, through charging circuitry coupled toa battery interface 254 such as the data port 230. The battery 256 canprovide electrical power to at least some of the electrical circuitry inthe electronic device 102, and the battery interface 254 provides amechanical and electrical connection for the battery 256. The batteryinterface 254 is coupled to a regulator (not shown) which provides powerV+to the circuitry of the base unit 104.

The user interface 390 can include an input system or an output systemor both. For example, the input system can include a keyboard,touchscreen, or a mouse and the output system can include a speaker ordisplay. The input system can be used to enter data into, access datafrom, or organize data in memory (e.g. ROM 248). The output system canbe used to display or provide data from memory (e.g. RAM 226 or ROM248).

The base unit 104 can monitor the conditions of the communicationnetwork 100. For example, the base unit 104 can listen to transmissionson the communication network 100 and can use embedded statisticalinformation in the messages, and data from polling remote units 102 todetermine the levels of usage of the network resources and to determinethe congestion on one or more transmission path in the communicationnetwork 100. The base unit 104 can keep historical data concerning theusage levels of the communication network 100. This historical data canbe used to determine whether the communication network 100 (or specifictransmission paths) is experiencing an increasing in traffic forexample.

Asynchronous Ubiquitous Protocol

In one or more embodiments, the base unit 104 periodically broadcasts arequest message to the remote units 102 in the communication network100. The request message can be a message that requests for any eventdata to be transmitted from the remote units 102. For example, if aremote unit 102 is experiencing a particular event it will transmit dataidentifying the event (e.g. an event code) to the base unit 104 inresponse to the request message.

The request message can identify or include Asynchronous UbiquitousProtocol. The Asynchronous Ubiquitous Protocol can be defined at thebase unit 104 and can be a schedule of a plurality of time slots, witheach time slot defined by a distinct start time and end time pairs.

The Asynchronous Ubiquitous Protocol is a schedule for organizing thetransmission of data from remote units 102 to the base unit 104 (or tobase collectors 106). The Asynchronous Ubiquitous Protocol sets a lengthof time for one or more data transmissions from the remote units 102.The Asynchronous Ubiquitous Protocol (e.g. the length of time for thedata transmissions) repeats periodically so that the AsynchronousUbiquitous Protocol can be arranged (by the base unit 104) to beginafter a predetermined amount of time (e.g. 100 milliseconds) after thecompletion of the previous Asynchronous Ubiquitous Protocol hascompleted.

FIG. 4 depicts a schematic diagram of an exemplary AsynchronousUbiquitous Protocol (APP) 400. The AUP 400 intended to represent aschedule of future time slots within which the remote units 102 cantransmit event data, if necessary. The AUP 400 includes an AUP starttime 402, an AUP end time 404, and a set of slots 408 defined by starttimes and end times 410 all on a time duration 406 (e.g. milliseconds).For example, each time slot 408 is defined by a start time and end timepair (e.g. two successive delineations 410 in the time duration 406).

The time duration 406 is such that there is a set period of time betweenthe AUP start time 402 and the AUP end time 404.

The AUP start time 402 is the precise time when the AUP 400 is set orsynchronized to begin and the AUP end time 404 is the precise time whenthe AUP 400 is set or synchronized to end. The AUP start time 402 andthe AUP end time 404 can be periodic start and end times. For example,the AUP start time 402 and the AUP end time 404 can be synchronized bythe base unit 104 so that each remote unit 102 is operating with thesame periodic AUP start time 402 and AUP end time 404. By way of furtherexample the AUP start time 402 (and corresponding AUP end time 404) canrepresent multiple periodic start times throughout a time period (e.g. aday) such that no complete AUP 400 overlaps with a subsequent AUP 400.

Between the AUP start time 402 and the AUP end time 404 are a number oftime slots 408 defined by time delineations 410. The time delineations401 may also be referred to as start times 410 or end times 410 (orpairs of start times 410 and end times 410) in reference to a time slot408. The time slot 408 represents the time period between two successivetime delineations 410. The length of time in a time slot 408 can bearranged or configured (e.g. by the base unit 104) to be an adequatelength of time for transmitting an event occurrence for example.

The base unit 104 (e.g. through the operation of its processor 238) canbe configured to dynamically change the AUP 400 depending on the networkconditions as monitored by the base unit 104. For example, the base unit104 may determine that the network performance conditions are slower(i.e. more congested) than normal, in such a case it may increase thenumber of time slots 408 and thus lengthen the AUP duration.Consequently, the base unit 104 may lengthen the time between the AUPstart time 404 and the AUP end time 402. By way of further example, thebase unit 104 may determine (from monitoring the communication network100) that the network performance conditions are faster than normal(i.e. less congested). In such a situation the base unit 104 maydecrease the number of time slots 408 and thus decrease the AUPduration.

Exemplary Method of Operation

FIG. 5 depicts an exemplary method 500 of requesting data from a set ofremote units 102 in a network 100. The method 500 may be carried outusing a processor 238 operating on instructions stored in a memory 226,248 of the base unit 104.

At 502, an Asynchronous Ubiquitous Protocol (“APP”) is defined. The AUP400 can be a schedule of a plurality of time slots, each time slotdefined by a distinct start time and end time pair. For example, the AUP400 can be the AUP 400 described in FIG. 4.

The start time and end time pairs can define a set of non-overlappingtime slots within which data may be transmitted. For example, the AUP400 can be made up of 10 time slots each of 150 milliseconds in length.In another example, the time slots are not of uniform length.

The base unit 104 can be responsible for synchronizing the remote units102 in the network 100. For example, the base unit 104 may inform theremote units 102 (or the base collectors 106) of the time throughout theday when the AUP 400 is scheduled to start (e.g. when the AUP start time404 will occur). In other words, the base unit 104 can synchronize theother components in the communication network 100 to operate with thesame start times for the AUP 400. For example, the base unit 104 mayinform the remote units 102 (or the base collector 106) that the AUPstart time 404 occurs every 500 milliseconds. The base unit 104 canreset or re-synchronize the components in the communication network 100depending on changes to the AUP 400, for example, or depending oncommunication network 100 conditions (as determined at the base unit104).

At 504, the transmitting instructions can be broadcast to the set ofremote units 102. The transmitting instructions can include the AUP 400and selection instructions for selecting a time slot 408 from the AUP400 to use for data transmission. The transmitting instruction can alsoinclude synchronization instructions for synchronizing the remote units102 (and base collector 106, e.g.) with the AUP start times 404.

The base unit 104 can be configured to periodically transmit APPs 402 tothe remote units 102 in the network 100. The base unit 104 may broadcastthe AUP 400 to the remote units 102 in response to changes made to theAUP 400. Each time slot 408 in the AUP 400 may be enumerated for ease ofreference.

The instructions for selecting a time slot 408 from the AUP 400 caninclude selecting a time slot 408 based on selected digits of the serialnumber of the remote unit 102. For example, the base unit 104 mayinstruct the remote units 102 to select a time slot 408 based on thelast two digits of the remote unit's 102 serial number. By way offurther example, the base unit 104 may provide a mapping to the remoteunits 102 (e.g. along with the instructions) that provides a mappingfrom the last two digits (or of the selected digits) of the serialnumber of the remote unit 102 to a specific time slot 408.

The instructions for selecting a time slot 408 from the AUP 400 caninclude instructions to select a time slot 408 based on a pseudo-randomnumber. For example, the instructions can include a request to theremote units 102 (or particular remote units 102) to use a random orpseudo-random number generator to select one slot to use to transmitdata.

The pseudo-random number that is generated can then be mapped to one ofthe enumerated time slots 408. For example, the base unit 104 canprovide the remote units 102 with a mapping to be used to map thegenerated number (e.g. pseudo-random number) to a time slot 408.

The instructions for selecting a time slot 408 from the AUP 400 caninclude instructions to select a time slot based on the geo-location ofthe remote unit 102. For example, the instructions can include a mappingfrom specific geo-locations to specifically enumerated time slots 408.In one or more embodiments, the base unit 104 can instruct specificremote units 102 to use specific time slots 408 in the AUP 400.

At 506 data transmitted from a remote unit 102 in the set of remoteunits is received in accordance with the transmitting instructions. Theremote unit 102 can begin transmission of the data at or after the starttime 410 of its time slot 408 and finish the transmission of the databefore or at the end time 410 of its time slot 408.

In one or more embodiments, the data received at the base unit 104 andthat is transmitted from one or more of the set of the remote units 102is extracted from the time slot 408. For example, the base unit 104 canextract the data during the time slots 408 set out in the AUP 400.

For example, the base unit 104 can determine the commencement of thefirst time slot 408 (in the enumerated time slots 408 in the AUP 400)and can process the data in each succeeding time slot. The processing ofthe data can include extracting or reading the data within the time slot408. The data extracted from within each time slot can be separatelyprocessed and stored in a memory 226, 248 associated with the base unit104.

For example, data from remote unit 102 A can be received within thefirst time slot 408, data from remote unit 102 B can be received withinthe second time slot 408 and data from remote unit 102 C can be receivedwithin the third time slot 408. By way of further example, data fromremote unit 102 A can be received within the second time slot of a firstAUP 400, then data from remote unit 102 B can be received within theseventh time slot of the first AUP 400, and then data from remote unit102 C can be received within the third time slot of the second AUP 400(e.g. after data from remote unit 102 B is received).

In one or more embodiments, the data may be transmitted from the remoteunits 102 using a single RF channel. Similarly, the instructionstransmitted from the base unit can be broadcast on the same single RFchannel.

Optionally, at 508 an acknowledgment message is transmitted to theremote unit 102. The acknowledgment message can be transmitted from thebase unit 104 to the remote unit 102. For example, the acknowledgementmessage can be broadcast to the remote units and can include informationthat identifies the remote unit 104 as the recipient. The acknowledgmentmessage can consist of an indication that the base unit 104 received thedata transmitted from the remote unit 102.

In an embodiment of the network 100, the base unit 104 may include theinformation of the transmission path, through which it receives amessage from a remote unit 102, in an acknowledgment message. Bybroadcasting the acknowledgment message in the network 100, all remoteunits 102 receive the transmission path information. Each remote unit102 contains a database (e.g. in memory) of all routes that reach thebase unit 104 via different remote units 102 and is capable to make acomplete view of the network topology, to find all possible and the bestpath towards base unit 104.

Optionally, at 501, one or more conditions of the network 100 can bemonitored by the base unit 104. The base unit 104 can then define (orredefine) the AUP 400 based on these monitored conditions. Themonitoring can be an ongoing process or can occur periodically (e.g. thebase unit 104 can run multiple concurrent processes). For example, thebase unit 104 can monitor the network during each occurrence of the AUP400 (e.g. in between the AUP start time 404 and AUP end time 402).

The conditions that are monitored are generally those that reflect thecongestion or level of traffic (e.g. data transmissions) on the network100. By way of further example, the conditions that are monitored caninclude monitoring a specific remote unit 102 or a specific geographicallocation which may contain a set of remote units 102. In yet a furtherexample, the conditions that are monitored may include monitoring thesignal strength on one or more RF channels that may be used on thenetwork 100.

In one or more embodiments, one or more conditions that are monitoredcan include the rate of retransmission of data across the network 100.For example, an increased rate of data retransmission can imply that thenetwork 100 is becoming more congested. In such a case, the base unit104 may redefine the AUP 400 to include longer duration of an AUP 400and consequently more time slots 408 in the AUP 400. This may be able toaccommodate data from remote units that may not otherwise be able to besent on time (e.g. by the start time 410 of the time slot 408).

Another condition that can be monitored can be the number of pollrequest from remote units 102. Remote units 102 may transmit pollrequests for various reasons, such as to help establish a transmissionroute, to initiate a communication session with the base unit 104, orfor various other reasons. However, an increase in the number of pollrequests can imply that the network 100 is becoming more congested. Thiscan be because more remote units 102 are attempting to establish moreefficient transmission routes, for example. In such a case, the baseunit 104 may redefine the AUP 400 to include longer duration (andpotentially fewer) time slots 408. This may be able to accommodate datafrom remote units that may not otherwise be able to be sent on time(e.g. by the start time 404 of the time slot 408).

Another condition that can be monitored can be the usage of the timeslots 408 in the AUP 400. For example, an increase in the number oftimeslots within which data is not transmitted or included can implythat the communication network 100 can handle a higher rate of datatransmissions involving the remote units 102. In response to thiscondition of the communication network 100, the base unit 104 mayredefine the AUP 400 to reduce the number of time slots 408 and theconsequently length of time for an AUP 400. This may result in fastertransmission of data from the remote units 104 that have events toreport because of the shorter wait time between AUP start times 404. Asnoted, upon reconfiguration of the AUP 400, the base unit 104 canresynchronize the remote units 102 (to be on schedule with the AUP starttimes 404).

Optionally, at 512, the data is associated with a remote unit 102 basedon a portion of the extracted data. In other words, the data transmittedbetween an AUP start time 404 and

AUP end time 402 pair is associated with a single remote unit 102. Suchdata can include an identification of the remote unit 102 from which itoriginated. When the base unit 104 extracts or reads or processes suchdata, the base unit 104 will be able to determine from the data theidentity of a remote unit 102. The base unit 104 can the associate thereceived data with that remote unit 102 (e.g. in a memory 226, 248associated with the base unit 104).

In an embodiment, at 514, one or more remote units 102 is polleddirectly to request polling data. For example, the base unit 104 cantransmit a polling message to a particular remote unit 102 to requestpolling data. For example, the polling message can be broadcast and caninclude the identity of the remote unit 102 that is being polled.

The polling data can include a confirmation of the existence that afunctioning transmission path from the remote unit 102 to the base unit104. The polling data can include an identification of the hops takenalong the path. For example, referring to FIG. 1, the transmission pathfrom remote unit 102 C to the base unit 104 can be as follows: remoteunit 102 C to remote unit 102 B to remote unit 102 A to the base unit104. The polling data transmitted from remote unit 102 C can identifythis transmission path.

The polling request from the base unit 104 can include a request for theremote unit 102 to transmit the polling data (or to use) a particulartransmission path. The base unit 104 can maintain a topology of thetransmission paths in the communication network 100 in memory 226, 248.The polling data that is received from a remote unit 102 can be used toupdate this topology information. If not polling data is received aftera predetermined or set period of time, then the base unit 104 willassume that the particular transmission path is not operational.

The data transmitted from the remote unit 102 can include a request totransmit a long message. The long message can be a message that takeslonger to transmit than a duration of the time slot 408. The duration ofthe time slot 408 is the time that elapses between the start time 410and the end time 410 pair that define the time slot 408 underconsideration. For example, the remote unit 102 may be synchronized totransmit data within one of the time slots in the AUP 400, which may beoccurring periodically. The remote unit 102 may determine that itsmessage cannot be fully transmitted within the time period allotted toits time slot 408. The request to transmit a long message can alsoinclude the length of the long message.

If the data transmitted includes a request to transmit a long messagethen, optionally, at 516, in response to receiving the data transmittedfrom the remote unit 102, a polling request is transmitted directly tothe remote unit 102 to request the long message. The polling request caninclude a time period within which the remote unit 102 can transmit thelong message. The time period can be selected by the base unit 104 toaccommodate the transmission of the long message, based on the expectedlength of the long message (which may have been provided in the requestto transmit a long message or which may be previously known to the baseunit 104). The starting time of the time period can be selected to besuch that the time period does not overlapping with an upcoming AUP 400.Similarly, if necessary, the base unit 104 can redefine the AUP 400 toaccommodate the time period for the long message.

At 518 the long message can be received at the base unit 104. Forexample, the long message can be transmitted during the time periodallotted by the base unit 104 and can be transmitted in response to thepolling request sent directly to the remote unit 102 at 516.

At 520, an acknowledgement message can be transmitted from the base unit104 to the remote unit 102. The acknowledgement message can indicatethat the base unit received the long message. The acknowledgment messagecan be broadcast with an indication of the recipient remote unit 102 orit can be transmitted directly to the remote unit 102.

FIG. 6 depicts an exemplary method 600 of transmitting data from aremote unit 102 to a base unit 104. The method 600 described in relationto FIG. 6 can be carried out by a processor 238 executing instructionsstored on a memory 226, 248 associated with the base unit 104.

At 602 transmitting instructions are received from the base unit 104.The transmitting instructions can include an AUP 400 and instructionsfor selecting a time slot 408 from the AUP 400. The AUP 400 can includea schedule of a set of time slots 408 each defined by a start time 410and end time 410 pair. For example, the AUP 400 can be as described inrelation to FIG. 4.

The transmitting instructions are received at a remote unit 102. Theremote unit 102 can be constantly listening for data on thecommunication network 100. For example, the remote unit 102 can belistening for messages that are broadcast from the base unit 104, theremote unit 102 can be listening for polling messages transmitted fromthe base unit 104, the remote unit 102 can be listening fortransmissions from other remote units within its frequency range, andthe remote unit 102 can be listening for transmissions directly to itfrom the base unit 104.

The remote unit 102 can be an event reporting unit or another type ofmonitoring unit or system. The remote unit 102 can be associated with abuilding (e.g. a home or commercial establishment) that has a streetaddress. Upon installation of the remote unit 102 or shortly thereafterthe address of the remote unit 102 and the identity (e.g. serial number)of the remote unit 102 is stored in a memory associated with the baseunit 104. This can be performed manually, for example, through aninterface with the base unit 104. Address information and generallycustomer information can be stored in database (e.g. a memory) at thebase unit 104 before deployment of a remote unit 102 in the field. Theremote unit 102 can then be activated and its serial number can be usedto associate reported data (e.g. an event message from the remote unit102) with a client profile that may be stored in the database at thebase unit 104.

It is understood that each remote unit 102 has a unique serial numberwith which it can be identified.

At 604 a time slot 408 is selected from the AUP 400 within which totransmit remote unit data. The selection of the time slot 408 can bebased on the instructions for selecting the time slot 408 that werereceived at 602 as part of the transmitting instructions. For example,the instructions may indicate a method for selecting a time slot basedon a selection of digits in the serial number of the remote unit 102 orbased on a random or pseudo-random number. The remote unit 102 may havethe processing capability of a random or pseudo-random number generator.

The remote unit 102 can also have access to a mapping for use whenselecting a time slot 408. For example, the mapping may be transmittedto the remote unit 102 as part of the instructions. By way of furtherexample, the instructions may provide a procedure for selecting a number(e.g. using selected digit(s) of the remote unit's 102 serial number orusing a pseudo random number generator) and a mapping to translate thatnumber into one of the enumerated time slots 408.

After the enumerated time slot 408 is selected, the remote unit 102waits until the start time associated with that enumerated time slot 408(i.e. the start time of that time slot 408) and transmits the data, ifany.

The data may be event data consisting of an event code, which can bedeciphered or decoded by the base unit 104. The event data may beassociated with a sensed event at the location of the remote unit 102.For example, the remote unit 102 may be associated with or may be partof an event system that has one or more sensors. When the event systemsenses an unusual occurrence (e.g. a broken window or unrecognized entryinto a building) the remote unit 102 may transmit data that indicatesthe event of the unusual occurrence. There may be situations in whichthe remote unit 102 does not have any data to transmit, such as whenthere is no event occurrence. If there is no data to transmit, then theremote unit 102 disregards the instructions.

At 606, the data is transmitted to the base unit 104 in accordance withthe selected time slot 408. After the remote unit 102 has carried outthe instructions to select the time slot 408, the remote unit 102 waitsfor the start time for the next occurrence of the time slot 408 andtransmits the data with a destination of the base unit 104. When thedata is transmitted it can include the identification of the remote unit102 that sent the data, the identification of any hop units (e.g. otherremote units 102 or base collectors 106) along the transmission path andthe identification of the emergency event or other occurrence (e.g. theemergency code).

Optionally, at 608 an acknowledgment message is received from the baseunit 104. For example, the acknowledgement message can be broadcast fromthe base unit 104 and can indicate that the data was received at thebase unit 104.

Optionally, at 610 transmitting the data to the base unit 104 consistsof transmitting the data to a hop unit selected from an ordered list ofhop units stored at the remote unit 102, the ordered list of hop unitscomprising a list of units within transmission range of the remote unit102. For example, the hop units can consist of other remote units 102within frequency range of the remote units 102.

Optionally, at 612 the data transmitted from of the selected hop unit isthen monitored by the remote unit 102. This can occur when the remoteunit 102 transmits the data to a hop unit rather than the base unit 104.For example, with reference to FIG. 1, remote unit 102 B can transmitits data to remote unit 102 A, and then remote unit 102 B listens ormonitors for the transmissions from remote unit 102 A for apredetermined amount of time (e.g. 20 milliseconds) or for an amount oftime that is dependent on network performance conditions. Remote units102 can also monitor the data transmitted from the base collectors 104within its transmission range.

Optionally, at 614, if it is then determined that data was nottransmitted from the hop unit (e.g. remote unit 102 A, in the aboveexample) then, at 616, remote unit 102 B will transmit the data to thesecond remote unit 102 on its hop list, which may be ordered bypreference. For example, the second remote unit 102 on its hop list canbe remote unit 102 D.

In an embodiment, transmitting the data to the second hop unit caninclude reselecting a time slot 408 based on the instructions forselecting a time slot 408. For example, the instructions received by theremote unit 102 can include instructions for selecting a time slot 408for each successive attempt (e.g. instructions for selecting the timeslot 408 for the first hop unit on the ordered list and instructions forselecting the time slot 408 on the second hop unit on the ordered list).

In one or more embodiments, the data transmitted to the base includes arequest to transmit a long message. A long message may be predefined bythe base unit 104 and the remote unit to include a message that takeslonger to transmit than a duration of a time slot 408. In suchcircumstances, optionally, at 618, a polling request is then received totransmit the long message. The polling request can be sent directly tothe remote unit 102 or it can be broadcast by the base unit 104 with theidentification of the remote unit 102 and with an indication that it isa polling request for requesting the long message.

The remote unit 102 is provided (through the polling message) withtiming or synchronizing information in order to transmit the longmessage at a predefined time or time interval. The predefined time ortime interval can be in between two successive AUP 400 time durations.

At 620, again optionally, the long message is transmitted to the baseunit 104 from the remote unit 102.

At 622, an acknowledgement may then be received at the remote unit. Theacknowledgement may have been broadcast by the base unit 104 withinformation identifying the message as an acknowledgement of the receiptof the long message from the remote unit 102.

In one or more embodiments, the data transmissions on the communicationnetwork 100 may be performed using a single RF channel. For example, thedata may be transmitted by the remote unit 102 on the single RF channel.Similarly, the transmitting instructions may be received at the remoteunit on the single RF channel.

FIG. 7 is a schematic diagram of a remote unit 102 showing only a listof hop destinations 702 and eligible hop destinations 704 stored in amemory (e.g. ROM 226) associated with the remote unit 102. As noted,with reference to FIG. 7, each remote unit 102 can maintain a list ofhop destinations 702 and a list of eligible hop destinations 704. In theembodiment depicted in FIG. 7, there are 5 hop units in the list of hopdestinations 702 and 5 hop units in the list of eligible hopdestinations 704.

The list of hop destinations 702 for a specific remote unit 102 cancomprise the identity of the hop destinations that have shown to providehighest criteria for transmissions (or retransmission) of data from theremote unit 702 out of the hop units that are within transmission rangeof the remote unit 702. Similarly, the list of eligible hop destinations704 can consist of a specific number of hop units (for example, five hopunits) that are the next best hop units according to criteria forretransmission of data. Accordingly, the list of hop destinations 702can be an ordered list of hop destinations 702. The ordering is shown bythe arrows (e.g. 750) that are separating each hop unit.

The criteria for evaluating whether a hop unit is on the list of hopdestinations 702 or eligible hop destinations can be determined from theremote unit 102 listening for retransmissions from each hop unit (or hopdestination) in its frequency range. The criteria can then be used torank the hop units in order (for example the top 5) (i.e. the list ofhop destinations 702) and the next successive set of hop units in order(for example, the next ranking 6-10) (i.e. the eligible hop destinations704). In addition, the criteria can also be evaluated based on a pollingmessage transmitted from the remote unit 102 to the base unit 104through a transmission route involving one or more hop units. Forexample, the criteria can be used to determine whether an eligible hopunit is more favorable than a unit on the list of hop destinations 702.If so, the eligible hop unit replaces the unit on the list of hopdestinations 702. Alternatively, if there is space on the list of hopdestinations 702 (in some embodiments there may be a maximum size, whichmay be dynamic or set by the base unit 104, of the list of hopdestinations 702), then the identity of the eligible hop unit can thenbe moved to the list of hop destinations 702 and deleted from the listof eligible hop destinations 704.

By way of example, the criteria can include the percentage of successfulretransmissions from a hop unit (which may be determined from anacknowledgment message transmitted from the base unit 104 or another hopunit); the RSSI percentage (as compared to the strength of a messageoriginally transmitted from the remote unit 102; the geographic locationof the hop unit (which may be provided by the base unit 104, forexample); communication facilities at the hop unit, such as IPcapabilities; the number of hop units in the routing table of a hopunit; etc. In another example the latitude and longitude geographicalcoordinates of the originating and subsequent hop units can beincorporated in the data messages and polling responses of each unit sothat all neighboring units (e.g. remote units 102 within range) arefully informed on the network configuration topology

The hop destinations or hop units can be one or more of another remoteunit 102, the base unit 104 or a base collector 106.

The one or more embodiments, the hop destinations, or hop units caninclude any of the electronic devices shown in Table 1 below. Thecapabilities of each different type of hop unit are also shown in Table1.

In one or more embodiments, the list of hop destinations 702 or the listof eligible hop destinations 704 can be at least partially provided in apolling message from the base unit 104. The list of hop destinations 702and the list of eligible hop destinations 704 can be stored in a memory226, 228 associated with the remote unit 102. For example the memory canbe a buffer memory for easy and quick access.

FIG. 8 depicts a method 800 for managing one or more transmission routesfor a remote unit 102 in a communication network 100. The remote unit102 maintains a list of hop destinations 702.

At 802, a poll request is received from the base unit 104. The pollrequest can be transmitted over the communication network 100. Forexample, the poll request can be broadcast from the base 104 intendedfor receipt by a specific remote unit 102. In an alternative embodimentwhere the specific remote unit 102 is outside of the frequency range ofthe base unit 104, the remote unit 102 will periodically proactivelytransmit verification reporting messages.

The poll request is data initiated or prepared at the base unit 104(e.g. using the processor 238). For example, the poll request caninclude an identification of the remote unit 102. By way of furtherexample, the poll request can include an identification of the first hopdestination. When the remote unit 102 hears or receives the poll requestit can read the data to determine that it is the intended recipient andcan gather the other data included in the poll request. For example, ifthe poll request includes an identification of the first hopdestination, then the remote unit 102 can extract the identification ofthe first hop destination from the poll request (if the poll request wasintended for the remote unit 102) and it can transmit its response (e.g.a poll response) to the first hop destination.

At 804, in response to receiving the poll request, a poll response istransmitted to a first hop destination. For example, the remote unit 102to who the poll request was transmitted will transmit the poll responseto the first hop destination. The first hop destination can be chosen asthe first hop on the list of hop destinations 702.

The remote units 102 can transmit messages to a hop unit selected fromthe list of hop destinations 702 based on the criteria for the best hopunit or for ranking the hop units (as explained above). The hop units inthe list of hop destinations can thereby be ranks and the selection ofhop units to use can be rotated. For example, each successive successfultransmission of a message can be sent to the next hop unit in theranking. Similarly if a transmission to a hop unit is unsuccessful, thecriteria of that hop unit will be negatively affected and the remoteunit 102 will transmit the same message to the next hop unit in the listof ho destinations.

In one or more embodiments, the poll response can include data preparedat the remote unit 102. For example, the poll response (or poll responsedata) can include the identification of the first hop destination.Further, the poll response data can include information about the listof hop destinations 702 or the list of eligible hop destinations 704associated with the remote unit 102.

At 806, a transmission (or retransmission) of the poll message from thefirst hop destination is listened for by the remote unit 102 todetermine whether the first hop destination transmitted the pollmessage. For example, the remote unit 102 can listen for up to apredetermined amount of time to determine whether the poll message datawas successfully retransmitted by the hop unit. The remote unit 102 cankeep track of such data (e.g. the success rate or signal strength ofretransmissions from particular hop units) and can store it in a memory226, 248 for later use and evaluations. For example, such data can beused later as criteria for evaluating the ranking of certain hop unitsand to determine the set of hop units that are in the list of hopdestinations 702 and the set of hop units that are identified in theeligible hop destinations 704.

If the hop destination has not transmitted or retransmitted the pollmessage within the predetermined amount of time, the remote unit 102 mayconsider that the poll message was not successfully transmitted fromthat hop destination. In such a situation, the remote unit 102, at thenext polling request by the base unit 104 may then attempt to transmitthe poll message to the next hop destination in the list of hopdestinations 702.

In one or more embodiments, other remote units 102 can listen for thetransmission of data (e.g. the poll message) from the hop unit and canmake their own evaluations of the success of that hop unit.

In one or more embodiments, the hop unit adds data into the pollmessage. For example, the hop unit can add data into the poll messagethat identifies the hop unit. After the data passes through atransmission path to the base unit 104 (and potentially through one ormore additional hop units), the poll message can include anidentification of one or more of the hop units along the transmissionpath. The base unit 104 can then extract this data to determine theefficacy of such a transmission path.

At 808, the list of hop destinations 702 is updated based on whether thefirst hop destination retransmitted the poll message. For example, theremote unit 102 can update the criteria for evaluating whether the firsthop destination should be removed from the list of hop destinations 702.

In one or more embodiments, it may be determined (optionally), at 810,that the first hop destination did not transmit the poll message withinthe predetermined amount of time. In such a situation (optionally) at812, the first hop destination may be removed from the list of hopdestination 702 if the hop destination has had reached a thresholdnumber of successive failures and if there is an available hopdestination from an eligible hop list. The first hop destination may beadded to a black list maintained at the remote unit 102 or maintained atthe base unit 104. The black list is a list of hop destinations that arenot to be used or that are inactive. The first hop destination may onlybe added to the black list if it has been determined to be inactive in apredetermined number of successive attempts, for example.

The black list may be used for remote units 102 that are not to be usedfor an extended period of time. According to an embodiment, a remoteunit can be added to the black list only from the list of eligible hopdestinations 704, as follows: If a hop unit from the list of eligiblehop destinations 704 has a condition causing it to be listened to by theremote unit 102, but that the remote unit 102 cannot reach that hop uniton the list of eligible hop destinations 704, then the hop unit from thelist of eligible hop destinations 704 is placed on the black list. Thiscan be implemented in order to conserve processing resources.

In another embodiment, remote units 102 can be added into the black listfrom either the list of hop destinations 702 or the list of eligible hopdestinations 704 by direct instruction from the base unit 104 to theremote unit(s) 102.

A remote unit 102 (or hop unit) can be removed from the black list ifone of the following conditions occur: a time period (which may bedetermined at the base unit 104) for maintaining the remote unit 102 onthe black list expires; the base unit 104 directly remove the remoteunit 102 from the black list; or the communication network 100 or theremote unit 102 conditions change in a way that requires reorganizationof the list of hop destinations 702 and the list of eligible hopdestinations 704.

Optionally at 814, the poll message is transmitted to an eligible hopdestination from eligible hop list. As noted above, the eligible hoplist 704 can include the identification of one or more hop destinationsthat are not on the list of hop destinations 702 but that are in thefrequency range of the remote unit 102. The poll message may betransmitted to a hop unit on the list of eligible hop destinations 704after it is determined that the communication to all hop units in thelist of hop destinations 702 failed, each within a predetermined amountof time (at 810), for example.

Optionally at 816, it may be determined at the remote unit 102 that theeligible hop destination retransmitted the poll message. For example,the remote unit 102 may have been listening for transmissions from theeligible hop destination.

Optionally at 818, the identification of the eligible hop destination isadded the list of hop destinations 702 if the eligible hop destinationhas better qualifications than any of the hop units on the list of hopdestinations 702. For example, the hop destination on the list of hopdestinations 702 may be removed from the list of hop destinations 702(and may be placed on the list of eligible hop destinations 704) for theremote unit 102. This may be in response to step 816.

Optionally at 820, after the list of hop destinations 702 is updatedbased on whether the first hop destination retransmitted the pollmessage, the data transmitted from other remote units 102 withintransmission range of the remote unit 102 may be monitored. For example,the transmissions or retransmissions from other remote units 102 may bein response to other polling requests and may provide transmission routeinformation or hop destination criteria for further updating the list ofhop destinations 702 or the list of eligible hop destinations 704.

Optionally at 822, the ordering of the list of hop destinations 702 isupdated based on the monitored transmission data. For example, themonitored transmission data may provide criteria for ranking theefficiency or success of the hop units in the list of hop destinations702. For example, the list of hop destinations is updated based on oneor more of a target signal strength of the data transmitted from theremote units 102, the power level of the remote units 102, a rank of theremote units 102 and a traffic load on the remote units 102. The targetsignal strength can be in a predefined signal strength level of theinitial signal strength, for example. An example of a predefined signalstrength level is between 50% and 60%.

FIG. 9 is a flow chart showing an exemplary method 900 of managing thetransmission routes in a communication network 100. The communicationnetwork 100 can be the network described in relation to FIG. 1, suchthat the communication network 100 can include a base unit 104 and aplurality of remote unit 102.

At 901, optionally, a first remote unit 102 is selected based on networktopology data stored at the base unit 104 (e.g. in memory 226, 248). Thefirst remote unit 102 is one of the plurality of remote units 102 in thecommunication network 100.

At 902, a first poll request is transmitted to the first remote unit102. For example, the first poll request can be transmitted by the baseunit 104 using a targeted message or a broadcast.

At 904, a polling response from the first remote unit 102 in response tothe first polling request is listened for. For example, the base unit104 can listen for a response from the first remote unit 102, which maytravel through one or more transmission routes in the communicationnetwork 100.

The polling response can include an identification of at least one hopdestination associated with the first remote unit 102. For example, theat least one hop destination identified in the polling response can be ahop unit that was passed through in the transmission route to the baseunit 104. By way of further example, the polling response may includeinformation regarding the first remote unit 102 such as the following:remote unit 102 power level, the number of hop units in the list ofeligible hop destinations 704 for that remote unit 102, the number ofhop units in its list of hop destinations 702, the number of messages ina memory buffer of remote unit 102, geographical zone informationassociated with the remote unit 102, remote unit 102 rank information,hop distance to base unit 104, geographical coordinates (latitude andlongitude, hardware configuration, firmware version, unit status,traffic information), etc.

At 906, a network topology data stored in a memory 226, 248 associatedwith the base unit 104 is updated based on the polling response. Thenetwork topology data can include identities of one or more remote units102 in the communication network 100 and the geolocations (orgeographical zones) of one or more remote units 102 in the communicationnetwork 100.

In one or more embodiments, such as when the polling response includesdata indicating a hop destination on the transmission route, the networktopology data is updated to indicate that the transmission route betweenthe first remote unit 102 and the at least one hop destination isactive. By way of further example, first polling response can alsoinclude the geographic location of the hop destination and the networktopology data can be updated to include the geographic location of thehop destination.

In one or more embodiments, the network topology data also includes oneor more transmission path between the remote units 102 and the base unit104. The transmission paths can be defined as ordered sets of hopdestinations. In such embodiments, the polling response can also includedata associated with one or more transmission criteria associated withthe hop destination. Further, the network topology data can update theordered set of hop destinations using the on one or more transmissioncriteria associated with the hop destination.

In one or more embodiments, the polling request can include instructionsdirected to a remote unit 102 to respond to the polling request using aspecific transmission route. For example, the polling request canidentify the specific hop units to transmit the polling response throughin order to reach the base unit 104. For example, the network topologydata can include a list of destination hops (or hop units) associatedwith each remote unit 102. In such embodiments, the polling response maybe a null response indicating that no response was received. Optionally,at 908, it is determined that no response was received from the remoteunit 102. Further, at 910, the network topology data is updated toindicate that the specific transmission route (as identified in thepolling request) is inactive.

Optionally, at 912, it is determined that there is a new remote unit102. For example, a new remote unit 102 may have been installed at aspecific geographic location and is now ready or provisioned to beincluded in the communication network 100. The location and identity(e.g. serial number) of the new remote unit 102 may be entered into thememory 226, 248 of the base unit 104 manually, for example.

Optionally, at 914, a discovery poll request is transmitted to the newremote unit 102. The discovery poll request can be broadcast with theidentity of the new remote unit 102 so that the new remote unit 102 canreceive it.

It is understood that in some situations the remote unit 102 candetermine and select its own hop destination without directions from thebase unit 104.

Optionally, at 916, a discovery poll message is received from the newremote unit 102. For example, the discovery poll message can be receivedat the base unit 104 and can identify a list of hop destination 702stored at the new remote unit 102. The list of hop destinations 702includes a list of one or more hop destinations within transmissionrange of the new remote unit 102.

The various embodiments presented above are merely examples and are inno way meant to limit the scope of this application. Variations of theinnovations described herein will be apparent to persons of ordinaryskill in the art, such variations being within the intended scope of thepresent application. In particular, features from one or more of theabove-described example embodiments may be selected to createalternative example embodiments including a sub-combination of featureswhich may not be explicitly described above. In addition, features fromone or more of the above-described example embodiments may be selectedand combined to create alternative example embodiments including acombination of features which may not be explicitly described above.Features suitable for such combinations and sub-combinations would bereadily apparent to persons skilled in the art upon review of thepresent application as a whole. The subject matter described herein andin the recited claims intends to cover and embrace all suitable changesin technology.

What is claimed is:
 1. A method for requesting data from a set of remote units in a network, the method comprising: defining a schedule of a plurality of time slots, each time slot defined by a distinct start time and end time pair, the start time and end time pairs defining a set of non-overlapping time slots within which data may be transmitted, wherein the plurality of time slots of the schedule are unallocated time slots eligible to be selected by remote units; broadcasting the schedule; and receiving data transmitted from a remote unit in the set of remote units in accordance with the schedule, the data indicating an emergency event or occurrence.
 2. The method of claim 1 further comprising transmitting an acknowledgement message to the remote unit.
 3. The method of claim 1, wherein the number of times slots and the duration of the time slots are dynamic and dependent on performance of the network.
 4. The method of claim 1 further comprising: monitoring one or more conditions of the network, and wherein the schedule is defined based on the monitored one or more conditions.
 5. The method of claim 4 wherein the one or more conditions comprise one of: an increased rate of data retransmission; an increase in the number of poll requests from remote units; and an increase in the number of timeslots within which data is not included.
 6. The method of claim 1 wherein receiving data transmitted from one or more of the set of remote units comprises extracting data from one or more of the time slots.
 7. The method of claim 6 further comprising: associating the data with a remote unit based on a portion of the extracted data.
 8. The method of claim 1, wherein the remote unit is configured to select a time slot based on any one or more of: a serial number of the remote unit; a random number; a pseudo-random number; or a geo-location of the remote unit.
 9. The method of claim 1 further comprising, polling one or more remote units directly to request polling data.
 10. The method of claim 9 wherein the polling data comprises a confirmation of the existence that a functioning transmission path to the remote unit.
 11. The method of claim 1 wherein the data is received on a single radio frequency channel.
 12. The method of claim 11 wherein the schedule broadcast on the single radio frequency channel.
 13. The method of claim 1 wherein the data transmitted from the remote unit comprises a request to transmit a long message, wherein the long message comprises a message that takes longer to transmit than a duration of the time slot.
 14. The method of claim 13 further comprising: in response to receiving the data transmitted from the remote unit, transmitting a polling request directly to the remote unit to request the long message; receiving the long message; and transmitting an acknowledgement to the remote unit that the long message was received.
 15. A method of transmitting data, the method comprising: receiving, at a remote unit, a schedule, the schedule including a set of time slots each defined by a start time and end time pair, the start time and end time pairs defining a set of non-overlapping time slots within which data may be transmitted, wherein the time slots of the schedule are unallocated time slots eligible to be selected by remote unit; detect an emergency event or occurrence; selecting a time slot from the schedule within which to transmit remote unit data; and in response to detecting the emergency event or occurrence, transmitting the remote unit data in accordance with the selected time slot.
 16. The method of claim 15 further comprising receiving an acknowledgment message.
 17. The method of claim 15, further comprising transmitting the data to a hop unit selected from an ordered list of hop units stored at the remote unit, the ordered list of hop units comprising a list of units within transmission range of the remote unit.
 18. The method of claim 17, further comprising monitoring the data transmitted from of the selected hop unit.
 19. The method of claim 15, wherein the time slot is selected based on one or more of: a serial number of the remote unit; a random number; a pseudo-random number; or a geo-location of the remote unit.
 20. A communication network comprising: a set of one or more remote units, each remote unit arranged to transmit data; a base for communicating with the set of one or more remote units and for managing the communication network, the base associated with a processor, the processor configured to: define a schedule of plurality of time slots, each time slot defined by a distinct start time and end time pair, the start time and end time pairs defining a set of non-overlapping time slots within which data may be transmitted, wherein the plurality of time slots of the schedule are unallocated time slots eligible to be selected by remote units; and receive data transmitted from one of the remote units, the data indicating an emergency event or occurrence. 